Stationary contact structure and magnet support for an electromagnetic contactor



y 1963 D. J. ARNEBERG ET AL 3,391,359

STATIONARY CONTACT STRUCTURE AND MAGNET SUPPORT FOR AN ELECTROMAGNETICCONTACTOR Filed June 9, 1966 2 Sheets-Sheet 2.

51 awn/me.

United States Patent 3,391,359 STATIONARY CONTACT STRUCTURE AND MAG- NETSUPPORT FOR AN ELECTROMAGNETIC CONTACTOR Don .I. Arneberg and .Iordan F.Puetz, Milwaukee, Wis., assiguors to Square ll) Company, Park Ridge,Ill., a corporation of Michigan Filed June 9, 1966, Ser. No. 556,414 9Claims. (Cl. 335115) ABSTRACT OF THE DISCLOSURE A preferred stationarycontact structure and magnet support for an electromagnetic contactorembodying the present invention comprises a molded body which has acavity with a front opening and a top opening, each opening providing anentrance from the outside of the body into the cavity. A stationarycontact is inserted end foremost through the front opening and when soinserted is prevented from removal through the top opening by shouldersformed in the walls of the cavity. An element, which preferably is inthe form of a terminal connector, is inserted through the top openingand then detachably connected to the stationary contact. When soconnected, the connector is held against removal through the top openingby the contact and, in turn, engages shoulders in the cavity so as toprevent removal of the stationary contact through the front opening. Anelectromagnetic contactor is provided in the body and has a movablecontact cooperable with the stationary contact. The body is arranged sothat the electromagnetic structure can be readily installed and securedin the body with the core of the magnet cushioned so as to relieve theshocks imposed on it by the armature.

This invention relates to electromagnetic contactors, and particularlyto electromagnetic contactors in which the various operating parts canbe readily assembled and disassembled, and of which the parts themselvesare well adapted to quantity production.

An object is to provide an electromagnetic contactor in which a moldedbody comprising a cover and a base are configured so as to cooperatewith various operating parts of the contactor for holding them in properassembled relation to each other with a minimum of extraneous fasteningdevices.

A more specific object is to provide an electromagnetic contactor havingstationary contacts of types which can be installed readily in the coverof the body as desired by the user, and having an interlock which mayreadily be installed in the base of the body when desired.

Another specific object is to provide a bracket and bolt arrangementwhich performs the dual function of holding the cover and base inoperating relation to each other and the core of the electromagneticassembly in proper relation in the base and to cushion impact forcesincident to energization of the electromagnet.

Various other objects and advantages will become apparent from thefollowing illustrative example wherein reference is made to thedrawings, in which FIG. 1 is a front elevation of an electromagneticcontactor embodying the principles of the present invention;

FIG. 2 is a vertical, sectional view of the electromagnetic contactortaken on line 22 of FIG. 1, part thereof being shown in elevation forclearness in illustration;

FIG. 3 is a vertical section at right angles to the view of FIG. 2 andis taken on the line 33 in FIG. 2, part thereof being shown in elevationfor clearness in illustration;

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FIG. 4 is a top plan view of the contactor illustrated in FIG. 1;

FIG. 5 is a right end elevation of the contactor illustrated in FIG. 1;

FIG. 6 is a fragmentary horizontal view of the base of the body with thecover and contact carrier removed, and is taken on the line 6-6 in FIG.5;

FIG. 7 is an enlarged vertical sectional view of the form of stationarycontact assemblage illustrated in FIG. 1, and is taken on the line 77 inFIG. 1.

FIG. 8 is a perspective view of an interlock used in connection with thepresent invention, as viewed generally from the forward or outer facethereof;

FIG. 9 is a perspective View, similar to FIG. 8, of the interlock viewedfrom the opposite face thereof;

FIG. 10 is a perspective view of a type of bracket used for holding thecore of the electromagnetic means of the present invention in operatingposition in the base of the body;

FIG. 11 is an enlarged fragmentary perspective view of a portion of theelectromagnetic contactor with a modified form of stationary contactinstalled;

FIG. 12 is a bottom plan view, partly in section of a portion of thestructure illustrated in FIG. 11, showing the interlocking relationbetween the stationary contact and the cover of the electromagneticcontactor; and

FIG. 13 is a vertical sectional view through the contactor of FIGS. 11and 12, and is taken on the line 13-13 thereof.

For purposes of illustration and convenience in description, theelectromagnetic contactor is described herein as disposed in an uprightposition wherein its movable car rier operates in a vertical path, theother parts of the contactor being described in relation to thisposition. Accordingly, the terms vertical, horizontal, and the like, arenot absolute but are merely to define more readily the relativepositions of the operating parts.

Referring to the drawings, the contactor, indicated generally at 1,comprises a base 2 and a cover 3 secured to gether by suitable bolts 4.The base is molded in one piece and is provided with an open top maincavity 5 and a pair of open top auxiliary cavities 6 which are disposedalongside diagonally oposite portions of the main cavity 5 and are incommunication therewith.

Mounted within the cavity 5 and extending upwardly through the open topthereof, is a movable contact carrier 8 carrying a plurality of movablecontacts 9 each of which is held in position relative to the carrier byan associated spring 10. The carrier 8 has two lateral depending endportions 12 which are guided by suitable upright guideways in the maincavity 5 and interval therewith. At their lower ends the portions 12support an armature 13. A suitable snap-fastening bracket 15 is providedfor securing the armature detachably in fixed position on the lower endof the carrier portions 12. This bracket comprises a strip of metalhaving upwardly extending arms 15a, each with a flange 15b at its upperend detachably engaging a suitable notch in the associated one of theportions 12 of the carrier. The bracket its provided with fingers 15cwhich engage the front and rear of the armature and, with the arms 15a,constraining the armature in fixed relation to the carrier 12.

The base 2, cover 3, and carrier 8 each is molded in one piece ofsuitable rigid electrical insulating material.

Also mounted within the cavity 5 is an electromagnetic coil 17 which ispreferably encased in a molded body 18 which rests on bosses 19 in thecavity 5 of the base 2. The shoulders 19 constrain the coil frommovement downwardly in the cavity 5 beyond a predetermined position.

Mounted within the cavity is an iron core 20 having a dependent centralpole 20a and two dependent outer shaded poles 20b. The central pole 26aextends through coil 17, and it and the poles b terminate normally inspaced relation above the armature 13. The poles 20]) are shaded, asillustrated.

In order to cushion the impact forces incident to energization of themagnet, a bracket 21, which is best illustrated in FIG. 10, is provided.For cooperation with the bracket, the base 2 is provided at twodiagonally opposite corners with exterior downwardly facing shoulders 22and the cover is provided with an aligned upwardly facing shoulder 23.The cover and base have aligned passages extending through the shoulders22 and 23 for accommodating the screw 4.

The bracket 21 has an upper laterally directed resilient portion 25which extends between the upper end of the base 2 and lower end of thecover 3 and which may engage, but preferably lies in slightly spacedoverhanging relation to, an upwardly facing surface portion of the core20. The bracket is provided with a lower laterally directed portion 26which, when the upper lateral finger or portion 25 is in its operatingposition, is juxtaposed against the shoulder 22. Thus the portion 25 isengaged by the core 20, as the core jumps upwardly when struck by thearmature 13 upon energization of the magnet, and cushions the shocksthat would otherwise result from the impact forces. Two such bracketsare provided, one at diagonally opposite corners of the contactor.

For economy in manufacture and assembly the lower lateral portions 26 ofthe brackets 21 may be internally threaded for threaded engagement withthe lower end of the screws 4.

The bracket 21 is preferably fitted so that its upright intermediateportion lies in a suitable groove 27 formed in the base 1, as bestillustrated in FIG. 9, so as to present exteriorly of the contactor asurface flush with the side wall of the base.

The cover 3 has internal cavities 30 in which the upper end portion ofthe carrier 8 projects. Suitable return springs 31 are disposed betweenthe upper end wall of the cavities 30 and the upper end of the carrierand yieldably urge the carrier downwardly to its fully lowered positionillustrated in FIG. 3.

The cover is provided with forwardly and rearwardly extending uprightouter side walls 32, intermediate barrier walls 32a parallel to thewalls 32, and a central wall 33. These walls form, with other portionsof the cover, a plurality of cavities 34, one between each two adjacentforwardly and rearwardly extending walls at each side of the centralwall 33. Each of the cavities 34 is open at the front and closed at therear. It is to be understood that front is used for clarity inillustration to define the end of a cavity 34 which is opposite from thecentral wall 33, even though cavities at one side of the wall 33 open ina direction forwardly of the cover as a whole and those at the oppositeside of the wall 33 open rearwardly of the base as a whole. Each of thecavities 34 has an upwardly facing shoulder 35 at its forward end and isclosed at the rear by the central wall 33. The side walls of each cavityare provided with bosses 36, respectively, which extend horizontallyforwardly and rearwardly of the cavity. Each of the bosses 36 has anupwardly facing shoulder 37 and a downwardly facing shoulder 38, and aflat upright face facing transversely of the cavity 34. At the front ofeach cavity 34 parallel upright shoulders 39 are provided on, and areintegral with, the side walls, respectively. Each shoulder 39 issomewhat curvilinear and convex inwardly of the cavity at its upperportion 39a. A stationary contact 40 is mounted within each of thecavities. Each contact 46 is in the form of a strip of metal bent sothat in side elevation it has a lower contact portion 41, an upperconnecting portion 42, a depending forward portion 43, and a rear neckportion 44. The portion 42 may be provided at its opposite lateral edgeswith tines 4211 which are adapted to pass the shoulders 39 and cutslightly thereinto during in sertion of the contact into the cavity. Theneck portion 44 is of less width laterally, of the contact 40 or cavity34 in which it is disposed.

This width of the neck 44 is such that it can pass readily faceforwardly, between the upright faces of the bosses 36 of a cavity 34 asthe contact is inserted into an associated cavity 34 neck foremostthrough the open front end of the cavity. The contact is of such overallwidth that it can pass between the upright shoulders 39 during suchinsertion. Thus, the contact may be inserted through the forward openend of its associated cavity parallel to its operating position. When soinserted, the neck 44, as explained, has passed between the uprightfaces of the bosses 36. The bosses 36 are of such height that they fitbetween the underside of the upper portion 42 and the upper side of thelower portion 41 of the contact 40. Thus, when the contact is disposedfully within its cavity 34 so that the rear face of the neck 44 is inengagement with the wall 33, the bosses 36 are disposed between theupper and lower portions 41 and 42 and constrain the contact 40 frommovement upwardly out of its associated cavity 34. In this positionalso, the dependent portion 43 is preferably forwardly of the shoulders39 and may rest at its lower end on the shoulders 35, preferably flushwith the forward edge of the shoulders 39. Thus the contact 40 isconstrained from movement out of its cavity 34 in all directions exceptforwardly.

The contact is held in place forwardly and rearwardly by suitable meansengaging the cover 3. In the form illustrated in FIG. 1, the means forconstraining the contact 40 from movement forwardly out of its cavity 34comprises a terminal connector 46. The terminal connector is preferablyin the form of a strip of metal bent into O-shape in front elevation asviewed from the left in FIG. 7, and provided with an upper threaded bore47 and an aligned lower bore 48.

The terminal connector 46 is receivable through the open top of anassociated cavity 34 and is adapted to fit snugly, with operatingclearance, behind the rear of the shoulder 39a and to be secured to thetop of the contact 40 when in this position. For this purpose, it issecured in fixed position to top portion 42 of the contact 40 bysuitable screws 49 which extends through the lower bore 48 and is inthreaded engagement with the contact 40. Thus connected by engagementwith the shoulders 39, it constrains the contact 40 from movementforwardly out of its associated cavity 34. A suitable connecting screw50 in the upper bore 47 of the terminal connector 46 is adapted to bescrewed downwardly to secure a wire or other terminal between the upperend of the bolt 4? and the screw 50.

The installation of the stationary contacts in the cover is onedepending upon the type of stationary contacts employed. The type ofcontacts heretofore described are merely slid into the cavities 34through the front ends thereof and in engagement with the shoulders ofthe bosses 36, in the position illustrated in FIGS. 1 through 4. Whilein this position, the terminal connectors 46 are inserted and secured bythe screws 49 to the stationary contacts 40, thus securing thestationary contacts from movement back out of the front end of theirrespective cavities. This installation is made before installation ofthe cover on the base.

It is apparent from the foregoing description that the electromagneticswitch may be readily assembled. For this purpose, all that is necessaryis to snap the desired movable contacts for the desired current ratinginto the carrier 8, assemble the core 20 and coil 17 and connect them tothe carrier 8 by first disposing the armature 13 in the bracket 15, andthen snap fastening the bracket onto the dependent portions 12 of thecarrier 8.

Next, the carrier with the electromagnetic means described are loweredint-o the main open top cavity 5 of the base 2, and when in placetherein the cover 3 is installed. The portions 25 of the brackets 21 areslid into place between the cover 3 and base 2 so as to overlie the stopof the core in spaced relation and limit its movement in a directiontoward the cover 3. The lower portions 26 of the brackets 21 are movedconcurrently beneath the shoulders 22, respectively. Thereupon, thecover 3, with its installed contacts, is applied and the screws 4 areinstalled for securing the cover to the base 2. The interlock switch, ifdesired, later to be described, is installed prior to the assemblage ofthe cover and the base, merely by pushing the interlock switch intoposition in the auxiliary cavity 6 in the base. It is held in place bythe installed cover.

Referring next to FIGS. 11 through 13, the modified form of stationarycontact 51 is provided. This contact is best illustrated in FIGS. 11 and12 and is essentially the same in general shape as the contactheretofore described. It comprises a strip of metal having a top portion52, a bottom portion 53, a front portion 54, and a rear or neck portionwhich, as in the case of the contact 40, is of less width than the otherportions so that the contact 51 can be slid into place neck foremostthrough the front of a cavity, such as the cavity heretofore described.As illustratedin FIG. 11, a portion of one of the forwardly andreadwardly extending walls of the cover is indicated at 56 and a portionof an intermediate or central wall is indicated at 57, thesecorresponding to the cover walls 32 and 33 heretofore described.

The two walls between which the contact 51 is slid have bosses, such asindicated at 58 in FIG. 13, which have adjacent faces faced so that theneck 55 can pass therebetween as the contact is inserted into thecavity. The upper and lower edges of the bosses 58 can engage the upperand lower margins of the contact to prevent its removal upwardly out ofthe cavity, all as in the case of the contact 40 shown in FIG. 2.Suitable shear nibs 59 may be provided on the bosses to assure aneffective fit of the contacts for frictionally holding them in positionand for compensating for manufacturing tolerance deviations. Also, toassure a tight fit, the portion 53 of the contact 51 may be slightlyoverformed so that it slopes upwardly forwardly. Then, when the contactis slid into place, the upper and lower portions thereof have a clampingengagement with the upper and lower edges of the bosses 58,respectively. If desired, the upper portion 52 may be provided withtines 60 at opposite lateral edges, these tines being adapted to passupright shoulders 62 on the side walls 56 and cut slightly thereintoduring insertion of the contact into its cavity. The lower portion 53 ofthe contactor is provided at its outer forward end with a notch 64 whichdefines at that end a pair of connecting ears 65 spaced apart laterallyof the contact. These ears are connected to the portion 53 by neckportions 66 of small cross section, formed by the notch 64 and lateralnotches 67. The neck portions are such that suitable screwdriver orother tool can be inserted between the ears 65 and twisted to spread theears apart so that their forward ends engage behind the shoulders 56a onthe walls 56 and thus constrain the contact from movement forwardly outof its cavity. By means of the ears 65 and shoulders 56a, the shoulders62, and cooperation of the upper portion 52 and lower portion 53 withthe bosses 58, the contactor is fixedly secured in place.

If desired, terminal connections may be provided by suitable screwsentering threaded openings 68 in the forward portion 54 of the contacts,respectively.

Again, if desired, the terminal connectors 69 may be secured to thecontacts 51 by means of bolts or screws 70. In this type of contactor itis desirable that the stationary contacts 51 be installed in the coverbefore installing the cover on the base, inasmuch as the bottom wallportions 53 thereof should be readily accessible by a tool through thebottom of the cover for spreading the ears 65 apart.

Referring next to FIGS. 1, 8 and 9, an interlock switch which may beinserted through the open top of the auxiliary cavity 6 is illustrated.

The interlock switch shown is a normally open switch.

It comprises a body 71 formed of two molded parts 71a and 71b ofinsulating material which may be placed into edgewise matching relation.Within the body 71 is a stationary contact 72 and a movable contact 73,the movable contact being mounted on a suitable spring finger 74 havinga cam surface 75. The finger 74, when unrestrained, holds the contact 73out of contact with the contact 72. Also mounted in suitable uprightslideways 76 in the body 71 is a slide 77 on which is a cam 78. In theform illustrated, the cam 78 is adapted to engage the cam surface of thefinger 74 for closing the contacts 72 and 73 when the slide 77 is movedupwardly. The slide is yieldably retained in its lowered position by areturn spring '79. A finger 80 on the slide 71 extends through anopening in the side of the cavity 6. A complementary finger 81 isprovided on the carrier 8. These fingers cooperate and provide means formoving the slide upwardly against the force of the spring 79 when thecarrier 8 is moved upwardly, thus causing closure of the contacts 72 and73.

A pad 82 of sponge rubber is secured to the bottom of the body 71 forresiliently urging the interlock switch upwardly into engagement withthe cover, thus compensating for manufacturing tolerance deviations.

If a normally closed interlock switch is desired, the cam surface 78 ismodified and positioned to engage the cam 75 and hold the contacts 72and 73 closed when the slide 77 is in its lowered position and torelease the contacts 72 and 73 for opening when the slide is in itsraised position.

Two such interlocks may be provided in a single contactor. If so, theyare arranged at diagonally opposite corners of the base 2 whereincorresponding auxiliary cavities 6 are provided, respectively.

Having thus described our invention, we claim:

1. An electromagnetic contactor comprising a body;

a movable contact carrier mounted therein;

a movable contact carried by the carrier;

said body having a pair of upright insulating walls in spaced face toface relation to each other and defining a contact accommodating cavityhaving a top opening and a front opening;

said openings providing entrances, respectively, from the outside of thebody into the cavity;

a stationary contact in the cavity, and adapted to be received in thecavity end foremost through one of said openings and to be removablefrom the cavity through said one of said openings;

sets of shoulders on the body within the cavity;

the shoulders of one set engaging the contact when the contact is in thecavity and constraining the contact from withdrawal through the other ofsaid openings; and

means received through the other of said openings and connected to thecontact and engaging the shoulders of the other set and constraining thecontact from withdrawal through said one of said openings, and beingconstrained by the contact from withdrawal through said other opening.

2. The structure according to claim 1 wherein said shoulders of theother set have portions facing away from said one opening; and

the means connected to the contact are a terminal connector :detachablyconnected to the contact and disposed at, and engaging, said portionsfacing away from said one opening.

3. The structure according to claim 1 wherein the means interconnectingthe contact and said shoulders of said other set comprise a pair of earson the contact at opposite lateral edges thereof, respectively, andnormally spaced apart edgewise from each other at their outermost limitstransversely of the contact a distance affording their entrance into thecavity through one of the openings past said shoulders of the other setupon insertion of the contact end foremost through said one of theopenings, and said ears being spread apart permanently edgewise in situinto interconnecting relation to said shoulders of the other set, whenthe contact is in said cavity.

4. The structure according to claim 1 wherein said body includes a baseand a cover;

the base has an upwardly open main cavity and an upwardly open auxiliarycavity disposed alongside the main cavity and in communication therewiththrough lateral walls of the cavities;

the carrier is in the main cavity;

guide means are provided in the main cavity and guide the carrier forupward and downward movement therein;

an interlock switch means is detachably accommodated in the auxiliarycavity and includes a stationary contact, a movable contact, and a slidefor controlling the making and breaking of contact the interlockcontacts;

means drivingly interconnect the carrier and slide;

the cover is detachably secured to the base; and

the stationary contact and cooperating shoulders are in the cover.

5. The structure according to claim 1 further including anelectromagnetic coil, a core for the coil, and an armature, said bodyincludes a base and a detachable cover, said base has a cavity whereinthe movable carrier, coil, core, and armature are contained;

means in the base cavity constraining the core from movement in adirection away from the cover;

said base has an upright screw passage therein;

said cover has an upright screw passage aligned with the screw passageof the base;

said base has a downwardly facing shoulder spaced downwardly from thecover and through which the screw passage of the base opens at its lowerend;

a bracket having a main body portion and spaced upper and lower lateralportions, one of said portions engaging the underside of said downwardlyfacing shoulder and the other of said portions extending between thebase and cover and being operable to limit movement of the core towardthe cover;

a bolt received through the passages and connected to said one lateralportion of the bracket and thereby holding the cover, bracket, and bodytogether, and limiting said movement of the core toward the cover by thebracket.

6. The structure according to claim 5 wherein said one lateral portionis juxtaposed against said downwardly facing shoulder and has aninternally threaded passage aligned with the screw passage and inthreaded engagement with the bolt.

7. The structure according to claim 5 wherein the core is supported inthe body for movement in a direction toward the core by impact forcesimposed on the core by the armature when the coil is energized, saidother of said portions is spaced slightly from the core in a directiontoward the cover, and said other of said portions is resilient andengageable by the core when the core is so moved partway toward thecover and is operative when so engaged to yieldably Oppose said movementand thereby cushion shocks caused by the impact forces.

8. An electromagnetic contactor comprising- -a body including a base anda cover;

said base having an upwardly open main cavity;

a movable contactor;

a movable contact carried thereby;

an electromagnetic coil;

a core for said coil;

an armature connected to the carrier and cooperable with the core;

said coil, core, and armature being disposed in said main cavity;

means in the main cavity guiding the armature for movement toward andaway from the cover;

said cover having a pair of upright insulating Walls in spaced face toface relation to each other and defining a contactor accommodatingcavity having a top opening and a front opening;

a stationary contact in the cover cavity;

sets of shoulders in the cover cavity, the shoulders of one set engagingthe contact and constraining the contact from withdrawal through one ofsaid openings;

means connected to the contact and engaging the shoulders of the otherset and constraining the contact from withdrawal through the other ofsaid openmgs;

said cover and base having aligned bolt openings therein;

means including a bolt extending through said aligned openings anddetachably connecting the cover to the base; and

said last mentioned means including a member secured in place on thebase by said bolt and having a portion engaging the core andconstraining the core from movement in a direction toward the cover.

9. An electromagnetic contactor comprising an electromagnetic coil, acore for the coil, and an armature, said body including a base and adetachable cover, said base having a cavity wherein the movable carrier,coil, core, and armature are contained;

means in the cavity constraining the core from movement in a directionaway from the cover;

said base having a pair of upright screw passages therein;

said cover having upright screw passages aligned with the screw passagesof the base, respectively;

said base having a pair of shoulders facing in a direction toward theend of the base opposite from the cover and through which the screwpassages of the base open, respectively, at their lower ends;

a pair of brackets each having a main body portion and lateral portions,one of said portions of each bracket engaging an associated one of saidshoulders and the other of said portions of each bracket extendingbetween the base and cover and engaging the core so as to limit movementof the core toward the cover;

bolts received through each pair, respectively, of aligned ones of saidpassages and connected to said first mentioned lateral portion of thebrackets, respectively, and thereby holding the cover, brackets, andbody together, and limiting said movement of the core toward the coverby the brackets.

References Cited UNITED STATES PATENTS 2,394,090 2/1946 McFarland335-196 2,539,628 1/ 1951 Kingdon 200-166 2,811,617 10/1957 Townsend200-166 2,945,098 7/1960 Ludwig 200-166 3,099,730 7/1963 Tateishi335-133 3,194,920 7/1965 Scheib 335-133 3,324,431 6/1967 Cataldo et al.335-197 2,361,808 10/1944 Ayers 335-277 3,060,355 10/1962 Kruzic 335-2773,088,058 4/1963 J'zikel 335-277 BERNARD A. GILHEANY, Primary Examiner.H. BROOME, Assistant Examiner.

